get ready for the counter arguement, If i'm able to keep my guns I will still want to grind for the new ones because they may potentially be better than my old guns, keeping old gear doesn't hurt a loot based game look at SWTOR for example, veractyls are old as -blam!- but people still lust after them and new cometics, people grind strikes there too for cash to trade/buy things off the GTN. being able to keep old gear is about not wanting to throw away everything you've worked towards how would you feel if you've played since day one but you get gally the day of or day before the 2.0 patch when it gets nerfed? or what if subsequently gjallahorn is made absolute shit but you have 1200-2000 hours into the game ? you'd feel like you just wasted a lot of time for nothing. if the new gear is good enough to stand in its own right it will replace peoples current gear as they delete old gear for the new gear, but if the new gear is shit people will just stay with old shit because the smells worn off.